Electrospun Nanofiber Membranes Research Articles

Functionalized electrospun nanofibers to enhance β-Galactosidase immobilization and catalytic activity for efficient galactooligosaccharide synthesis

This study aimed to immobilize β-galactosidase (β-GAL) into enhanced polystyrene (PS) electrospun nanofiber membranes (ENMs) with functionalized graphene oxide (GO). Initially, GO sheets were functionalized by salinization with 3-aminopropyl triethoxysilane (APTES). Then the ENMs (PS, PS/GO, and PS/GO-APTES) were prepared and characterized. Then, the β-GAL was immobilized in the different ENMs to produce the β-GAL-bound nanocomposites (PS-GAL, PS/GO-GAL, and PS/GO-APTES-GAL). Immobilization of β-GAL into PS/GO-APTES significantly improved enzyme adsorption by up to 87 %. Also, PS/GO-APTES-GAL improved the enzyme activity, where the highest enzyme activity was obtained at enzyme concentrations of 4 mg/L, 50 °C, and pH 4.5. Likewise, the storage stability and reusability of immobilized β-GAL were improved. Furthermore, this process led to enhanced catalytic behavior and transgalactosylation efficiency, where GOS synthesis (72 %) and lactose conversion (81 %) increased significantly compared to the free enzyme. Overall, the immobilized β-GAL produced in this study showed potential as an effective biocatalyst in the food industry.

Sulfonated cobalt phthalocyanine/NH2-MIL-125 heterojunction modified electrospun nanofiber membrane for emulsion separation and PMS-photocatalysis synergistic degradation

Membrane technology for wastewater remediation has generated significant interest, however, the single functionality, dull wettability and easy fouling property of the membrane hinder its practical application. Herein, a self-cleaning and multi-use superwetting nanofiber membrane was prepared by electrospinning and subsequent spraying technique. The sulfonated cobalt phthalocyanine/NH2-MIL-125 (CoPcS/NMIL) heterojunction was uniformly enrobed over polyethylene terephthalate (PET) electrospun membrane derived from waste PET bottles. The unique CoPcS/NMIL heterojunction exhibited a dual driving effect in photocatalytic activity and membrane wettability. Therefore, the fabricated CoPcS/NMIL@PET composite membrane demonstrated its capability to address complex water pollution issues effectively. The composite membrane exhibited notable flux permeation ability (538–3180 L m−2 h−1) and achieved excellent separation efficiency of over 99 % for diverse oil-in-water emulsions under the gravity filtration condition. Notably, the membrane can efficiently deal with stubborn high-viscosity crude oil fouling profiting from the photocatalytic self-cleaning function. A high flux recovery ratio of 93.6 % and a low irreversible fouling resistance ratio of 6.4 % can be obtained after 30 min of visible light irradiation. Impressively, CoPcS/NMIL@PET membrane exhibited enhanced permeation flux, separation efficiency and self-cleaning capacity compared to NMIL@PET membrane. Meanwhile, the CoPcS/NMIL@PET-activated peroxomonosulfate (PMS) system exhibited extremely high degradation performance for RhB under visible light with the degradation efficiency of 98 % within 10 min, suggesting its potential in the rapid purification of water-soluble organic pollutants. In addition, the CoPcS/NMIL@PET membrane has good chemical stability and mechanical properties for potential long-term use. Moreover, the demulsification mechanism in oil-water separation and PMS-photocatalysis synergetic mechanism over the fabricated CoPcS/NMIL@PET membrane were also investigated in detail. The research offers a promising approach for the design and fabrication of novel nanofiber membranes that incorporate photosensitizers and MOFs functional surfaces to address the challenges associated with such wastewater treatment.

Sustained-release of essential oils by polyvinyl alcohol-based nanofibers

Flavored cigarettes are very popular among consumers. However, many essential oils in cigarettes are lost during storage, and the utilization rate of the essential oils during use is low. Therefore, effective packaging and stable sustained release are urgently needed. In this study, a composite electrospun stable nanofiber storage material was prepared for sustained release. Polyethylene glycol, which has good heat storage properties, was selected as the heat storage material to inhibit the release of essential materials during storage. Porous graphene with good thermal conductivity and a porous structure was selected as the heat conductive component to ensure rapid and uniform release. Polyethylene glycol/porous graphene polyvinyl alcohol-mint essential oil sustained-release composite electrospun nanofibers membrane was prepared by electrospinning, and the morphology, composition, thermal properties, and sustained-release properties were tested. The results showed that the composite electrospun nanofiber membrane reduced the loss of mint oil during storage and enabled the rapid release of mint oil at high temperatures. At room temperature, the retention rate of the mint oil was still more than 90% after 120 h, and at a high temperature (75°C) the retention rate was less than 20% after 10 min; that is, 80% of the essential oil material was released within 10 min.

Preparation and good antibacterial properties of self-assembled P(AA-AM)/CA/GA fiber membrane by electrospinning

To reduce mortality rate caused by life-threatening bacterial infections, advanced antibacterial materials have attracted widespread attention from researchers worldwide. In this study, the antibacterial P(AA-AM)/CA/GA nanofiber membranes with pH-responsive properties were successfully prepared by facile electrospinning technology. A series of characterizations of the obtained nanofiber membranes showed the addition of P(AA-AM) improves the surface wettability of the as-spun fibers in comparison to those of CA and CA/GA nanofiber membranes. High-temperature treatment was found to enhance the mechanical properties of the P(AA-AM)/CA/GA membranes due to the crosslinking reactions. The prepared P(AA-AM)/CA/GA nanofiber membrane exhibits a pH-responsive effect which is evident by the change in GA’s release rate in solutions with different pH values. The cellulose acetate (CA) spinning nanofiber structure formed by P(AA-AM) coated GA also extended the release process of GA and improved the antibacterial timeliness of nanofiber membranes. The antibacterial experiments on E. coli and S. aureus showed that the electrospun nanofiber membranes containing GA had potent antibacterial properties, which were further enhanced by increasing the GA content in the P(AA-AM)/CA/GA blends. This study provides an insight into the design and preparation of pH-sensitive antibacterial materials using facile electrospinning technology.

Accelerated Wound Healing by Electrospun Multifunctional Fibers with Self-Powered Performance.

Wound healing has been a persistent clinical challenge for a long time. Electrical stimulation is an effective therapy with the potential to accelerate wound healing. In this work, the self-powered electrospun nanofiber membranes (triples) were constructed as multifunctional wound dressings with electrical stimulation and biochemical capabilities. Triple was composed of a hydrolyzable inner layer with antiseptic and hemostatic chitosan, a hydrophilic core layer loaded with conductive AgNWs, and a hydrophobic outer layer fabricated by self-powered PVDF. Triple exhibited presentable wettability and acceptable moisture permeability. Electrical performance tests indicated that triple can transmit electrical signals formed by the piezoelectric effect to the wound. High antibacterial activities were observed for triple against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, with inhibition rates of 96.52, 98.63, and 97.26%, respectively. In vitro cell assays demonstrated that triple cells showed satisfactory proliferation and mobility. A whole blood clotting test showed that triple can enhance hemostasis. The innovative self-powered multifunctional fibers presented in this work offer a promising approach to addressing complications and expediting the promotion of chronic wound healing.

Membrane hydrophobicity enhanced by non-solvent induced separation strategy for improving membrane distillation performance

Development of high-performance hydrophobic layer using green and economic method is still urgently on demand for wide applications of membrane distillation (MD). In this study, a novel Janus membrane was prepared by electrospinning polystyrene with the water addition on the surface of hydrophilic electrospun nanofiber substrate. With increasing water content to 3 wt%, the hydrophobic layer is completely converted to be nanofiber-dominate morphology that could be beneficial for water vapor permeation during MD process. The surface roughness, water contact angle value and porosity of the hydrophobic layer are enhanced by the water addition, and the optimized Janus membrane with the hydrophobic layer prepared at the water content of 2 wt% could achieve a high water flux of 33.1 L/m2h and superior salt rejection of >99.9 % when 3.5 wt% NaCl solution was used as the feed solution. The as-prepared Janus membrane shows better performance stability and reusability than the control membrane (without the water addition) within the 24-h continuous operation duration. Our work demonstrates that the proper water addition could be used as a green strategy for fabricating efficient electrospun nanofiber membranes for the direct contact membrane distillation (DCMD) processes.

Eye-Readable and Wearable Colorimetric Sensor Arrays for In Situ Monitoring of Volatile Organic Compounds.

Wearable sensors utilize changes in color as a response to physiological stimuli, making them easily recognizable by the naked eye. These colorimetric wearable sensors offer benefits such as easy readability, rapid responsiveness, cost-effectiveness, and straightforward manufacturing techniques. However, their applications in detecting volatile organic compounds (VOCs) in situ have been limited due to the low concentration of complex VOCs and complicated external interferences. Aiming to address these challenges, we introduced readable and wearable colorimetric sensing arrays with a microchannel structure and highly gas-sensitive materials for in situ detection of complex VOCs. The highly gas-sensitive materials were designed by loading gas-sensitive dyes into the porous metal-organic frameworks and further depositing the composites on the electrospun nanofiber membrane. The colorimetric sensor arrays were fabricated using various gas-sensitive composites, including eight dye/MOF composites that respond to various VOCs and two Pd2+/dye/MOF composites that respond to ethylene. This enables the specific recognition of multiple characteristic VOCs. A microfluidic channel made of polydimethylsiloxane (PDMS) was integrated with different colorimetric elements to create a wearable sensor array. It was attached to the surface of fruits to collect and monitor VOCs using the DenseNet classification method. As a proof of concept, we demonstrated the feasibility of the wearable sensing system in monitoring the ripening process of fruits by continuously measuring the VOC emissions from the skin of the fruit.

Gamma-irradiated janus electrospun nanofiber membranes for desalination and nuclear wastewater treatment

This study presents the fabrication of double-layer electrospun nanofibrous membranes (DL-ENMs) using polyvinylidene fluoride (PVDF) and polyether sulfone (PES) based polymers with different degrees of hydrophilicity (PES, sulfonated PES, and PES with hydroxyl terminals). A comparative analysis was carried out with single-layer electrospun nanofiber membranes (SL-ENM) with a total thickness of about 375 μm. Using feed solutions, including sodium chloride, sodium nitrate, and simulated nuclear wastewater (SNWW), the performance of DL-ENMs was evaluated for desalination and radionuclide decontamination by direct contact membrane distillation (DCMD) and air gap membrane distillation (AGMD) techniques. The results showed that DL-ENMs, especially those incorporating a sulfonated PES-based hydrophilic layer, exhibited superior permeate fluxes, reaching values of 72.72 kg/m2.h and 73.27 kg/m2.h in the DCMD using aqueous feed solutions of NaCl and NaNO3, respectively, and 70.80 kg/m2.h and 41.96 kg/m2.h using aqueous feed solutions of SNWW in DCMD and AGMD, respectively. Both SL-ENMs and DL-ENMs exhibited high rejection efficiencies and decontamination factors for the feed solutions (>99.9%). In addition, the prepared ENMs were exposed to gamma radiation to evaluate their applicability in real-life applications. The result of irradiation revealed the negative impact of gamma radiation on the fluorine content of PVDF which could be a critical point in using PVDF as a hydrophobic material for decontaminating nuclear wastewater by membrane distillation.

Skeleton-reinforced electrospun nanofiber membrane with enhanced mechanical strength

Electrospun membranes are made of thousands of nanofibers and are widely used in many fields. However, their poor mechanical properties seriously restrict their industrialization. In this paper, a simple post fabrication strategy is proposed to enhance the strength of electrospun nanofiber membranes. The polymer skeleton was melted electrohydrodynamic direct-writing into the electrospun nanofiber membrane and penetrated the nanofiber membrane to enhance its mechanical properties. As a verification, composite membrane with polyimide nanofiber and polylactide skeleton was generated, and tensile strength increased from 14.9 MPa to 34.2 MPa without significant loss of fiber morphology. In addition, finite element analysis was conducted. Our method makes it possible to predict the mechanical properties of nanofiber membranes in advance.

Salt-resistant and antibacterial polyvinyl alcohol/chitosan/silver-loaded graphene oxide electrospun nanofiber membrane for high-efficiency solar-driven desalination

To address the issues of low photothermal conversion efficiency, salt deposition and biological contamination in solar-powered desalination, we have developed nanofibrous membranes composed of an optimized ratio of silver-loaded graphene oxide (GO-Ag) composites and polyvinyl alcohol/chitosan (PVA/CS), using a simple and productive electrospinning technique. The synergistic effect of GO and Ag significantly enhanced the photothermal conversion efficiency of the dual-photothermal PVA/CS/GO-Ag-4% electrospun nanofiber membranes (EFMs), which achieved the pure water evaporation rate of 1.67 kg m−2 h−1 and photothermal conversion efficiency of 93.3% under 1 sun (1 kW m−2). Notably, 97% of optical energy is converted to heat when the PVA/CS/GO-Ag-4% EFMs were placed on a homemade evaporation device, achieving up to a simulated seawater evaporation rate of 1.64 kg m−2 h−1 under 1sun, with a desalination rate of 99.99%. More importantly, larger area EFMs are easier to prepare compared to other morphologies of solar evaporators, and larger membranes can be placed on outdoor evaporation units for large-scale effective desalination of seawater used to collect fresh water under natural light. Furthermore, PVA/CS/GO-Ag-4% EFMs exhibited outstanding antibacterial performance against Escherichia coli and Staphylococcus aureus. Considering these strengths, the PVA/CS/GO-Ag-4% EFMs has considerable application potential in solar-driven desalination to solve water crises.

Porous covalent organic framework nanofibrous membrane for excellent enrichment and ultra-high sensitivity detection of trace organochlorine pesticides in water

Developing adsorbents with high performance and long service life for effective extracting the trace organochlorine pesticides (OCPs) from real water is attracting numerous attentions. Herein, a self-standing covalent organic framework (COF-TpPa) membrane with fiber morphology was successfully synthesized by using electrospun nanofiber membranes as template and employed as solid-phase microextraction (SPME) coating for ultra-high sensitivity extraction and analysis of trace OCPs in water. The as-synthesized COF-TpPa membrane exhibited a high specific surface area (800.83 m2 g−1), stable nanofibrous structure, and excellent chemical and thermal stability. Based on the COF-TpPa membrane, a new SPME analytical method in conjunction with gas chromatography-mass spectrometry (GC–MS) was established. This proposed method possessed favorable linearity in concentration of 0.05–2000 ng L−1, high sensitivity with enrichment factors ranging from 2175 to 5846, low limits of detection (0.001–0.150 ng L−1), satisfactory precision (RSD < 10 %), and excellent repeatability (>150 cycles), which was better than most of the reported works. Additionally, the density functional theory (DFT) calculations and XPS results demonstrated that the outstanding enrichment performance of the COF-TpPa membrane was owing to synergistic effect of π–π stacking effects, high specific surface area and hydrogen bonding. This work will expect to extend the applications of COF membrane to captures trace organic pollutants in complex environmental water, as well as offer a multiscale interpretation for the design of effective adsorbents.

Current Update on Electrospun Nanofiber Mats as a Wound Healing Drug Carrier

Electrospun nanofiber mats are being researched as attractive wound-healing drug carriers owing to their exclusive features, large active surface area, interlinked porosity, and customizable drug release kinetics. These mats may be infused with antibiotics, growth hormones, or stem cells to hasten the process of healing and lessen the likelihood of problems. Controlled and sustained medication delivery is the key payback of electrospun nanofiber mats. Electrospun nanofiber mats promote wound healing in part because of the favorable milieu they provide cell adhesion and proliferation of the affected tissue due to their enhanced active surface area. Mats of many kinds are discussed in the review. Electrospun nanofiber membranes can be created in a diversity of configurations, along with a single layer, a coaxial structure, and many layers. Recent studies have shown the efficacy of using electrospun nanofiber mats to deliver a variety of therapeutic compounds for wound healing. Treatment of wound infections using antibiotic-loaded electrospun nanofiber mats may help slow the spread of antibiotic-resistant bacteria. Electrospun nanofiber mats supplemented with growth hormones are known to hasten wound healing by encouraging the local tissue’s proliferation and differentiation. Delivery of stem cells to the wound site, where they may develop into new skin cells and stimulate tissue regeneration, can be accomplished with the help of electrospun nanofiber mats. In conclusion, electrospun nanofiber mats provide an exciting new platform for the delivery of drugs to promote wound healing. Their enormous surface area, interconnected porosity, and adaptable drug release kinetics all make them excellent vehicles for delivering a wide range of therapeutic medicines to the wound site.

Anti-inflammatory and anti-oxidative electrospun nanofiber membrane promotes diabetic wound healing via macrophage modulation

BackgroundIn the inflammatory milieu of diabetic chronic wounds, macrophages undergo substantial metabolic reprogramming and play a pivotal role in orchestrating immune responses. Itaconic acid, primarily synthesized by inflammatory macrophages as a byproduct in the tricarboxylic acid cycle, has recently gained increasing attention as an immunomodulator. This study aims to assess the immunomodulatory capacity of an itaconic acid derivative, 4-Octyl itaconate (OI), which was covalently conjugated to electrospun nanofibers and investigated through in vitro studies and a full-thickness wound model of diabetic mice.ResultsOI was feasibly conjugated onto chitosan (CS), which was then grafted to electrospun polycaprolactone/gelatin (PG) nanofibers to obtain P/G-CS-OI membranes. The P/G-CS-OI membrane exhibited good mechanical strength, compliance, and biocompatibility. In addition, the sustained OI release endowed the nanofiber membrane with great antioxidative and anti-inflammatory activities as revealed in in vitro and in vivo studies. Specifically, the P/G-CS-OI membrane activated nuclear factor-erythroid-2-related factor 2 (NRF2) by alkylating Kelch-like ECH-associated protein 1 (KEAP1). This antioxidative response modulates macrophage polarization, leading to mitigated inflammatory responses, enhanced angiogenesis, and recovered re-epithelization, finally contributing to improved healing of mouse diabetic wounds.ConclusionsThe P/G-CS-OI nanofiber membrane shows good capacity in macrophage modulation and might be promising for diabetic chronic wound treatment.

A silver-loaded graphene oxide-functionalized Bi-Photothermal composite nanofiber membrane for solar-driven desalination

We have identified a synergistic effect between graphene oxide (GO) and silver (Ag) that significantly enhances the light absorption capacity of silver-loaded graphene oxide (GO-Ag) composite materials. Here we have developed a bi-photothermal electrospun nanofiber membrane (EFM), combining the GO-Ag and polyacrylonitrile (PAN), to improve solar-driven desalination. The characterization results demonstrate that GO-Ag uniformly dispersed within the fiber membrane as a photothermal conversion material enables the GO-Ag/PAN EFM to achieve a remarkable optical absorption of 97 %. And under 1 sun irradiation, the membranes rapidly reach a maximum temperature of 56.3 °C, showcasing exceptional photothermal conversion ability during evaporation. Additionally, the super-hydrophilic porous materials GO-Ag/PAN EFMs exhibit an impressive water evaporation rate of 1.61 kg m-2h−1, accompanied by a photothermal conversion efficiency of 93.3 % under 1 sun. Moreover, the GO-Ag/PAN EFMs demonstrate a remarkable desalination of 99.9 % and salt resistance performance for seawater.

A comprehensive review on removal of VOCs from air using fly ash as an adsorbent

Volatile Organic Compounds (VOCs) play a critical role in the atmosphere and are produced from biogenic and anthropogenic sources. These chemicals have serious health consequences for humans. Among many types of industrial waste available, Coal Fly Ash (CFA) are mostly produced by coal- fired power plants with the ability to capture VOCs from the air. The use of an inexpensive, high-performance electrospun nanofiber membrane to filter out airborne impurities. Adsorption is thought to be the best approach out of all of them due to its convenience, ease of usage, and easy-to-understand design. This review article covers the procedure, and environmental effects of employing fly ash for the adsorption of VOCs. The main concerns with fly ash disposal are the need for massive land areas for landfills and the harmful effects and groundwater pollution caused by the accumulation of heavy metals. Additionally, the methods for overcoming the benefits of using fly ash are also examined.

Fabrication of ε-Poly-L-lysine (ε-PL) modified electrospun antibacterial nanofibrous membranes for PM1.0 filtration

Segregating airborne particulate matters (PMs, especially PM1.0) with high transmissibility of bacterial and viral pathogens is crucial for ensuring outdoor breathing safety. Electrospun nanofiber membranes (ENMs) have shown great promise for this purpose. However, the application of traditional ENMs is usually plagued by bacterial growth causing severe public health concern. Although some research has been done to overcome this challenge by doping antibacterial materials, the potential negative effects of these materials on the human body cannot be ignored. In this study, the ε-Poly-L-lysine (ε-PL), a green broad-spectrum antibacterial reagent, was grafted onto the surface of polydopamine (PDA) coated polyacrylonitrile (PAN) ENM via addition of Schiff base and Michael reaction. Experimental results indicated that the introduction of the ε-PL is key to the antibacterial performance of the membranes, and the antibacterial efficacy of E. coli and B. subtilis can reach to 99.86 % and 99.99 % respectively. Even after 7 days, the antibacterial efficiency of membrane remained at a high level. Additionally, the uniform structure of membranes endowed it with a high filtration efficiency of 80.9 % for PM1.0 particles with a moderate transmembrane pressure drop (TMP) of 250 Pa and the corresponding quality factor is approximately 0.0066 Pa−1. This study has far-reaching implications for the design of green antibacterial nanofibrous membranes to realize the segregation of harmful PMs.

Incorporating TiO2 nanocages into electrospun nanofibrous membrane for efficient and anti-fouling membrane distillation

In this study, TiO2 nanocages with a hollow structure were integrated into the polyvinylidene fluoride co-hexafluoropropylene (PH) spinning solution, leading to the fabrication of a novel PH/TiO2 electrospun nanofiber membrane (PH/TiO2 ENM) through electrostatic spinning. The incorporation of TiO2 nanocages resulted in the formation of abundant micro-nano structures on the PH nanofiber surface, enhancing membrane roughness and hydrophobicity. Additionally, the hollow nanostructure of TiO2 nanocages effectively reduced the thermal conductivity of the ENMs. This reduction in thermal conductivity mitigated the temperature polarization effect, thereby increasing mass transfer driving force for the ENMs. The maximum water flux of the PH/TiO2 ENM reached ∼57.9 L m−2 h−1 (LMH), which was approximately 3.7 times higher than that of the original PH ENM. In addition to the formation of micro-nano structures on PH nanofibers, the presence of TiO2 nanocages facilitated the attachment of more low-surface-energy FAS molecules, improving the resistance of them to fouling and anti-wetting properties against both inorganic and organic contaminants, even in the presence of SDS, in a composite feed solution during the DCMD process. Moreover, even after prolonged exposure to a composite salt solution, this membrane also exhibited exceptional anti-fouling properties and stable desalination performance during a 168 h long-term stability test.

Water Treatment Performance of PAN/HPMC/Gr Nano Composites

This study investigates polyacrylonitrile:hydroxypropyl methylcellulose )PAN:HPMC( and PAN:HPMC: graphene (Gr) composite nanofibers prepared using the electrospinning technique. Electrospinning is a simple and versatile technique that relies on the electrostatic repulsion between surface charges to continuously draw nanofibers from a viscoelastic fluid. Membrane technology is vital in removing contaminants due to its easy handling and high efficiency. The results demonstrated that the Gr was successfully incorporated into the PAN:HPMC nanofiber membranes, as confirmed by scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) measurements. The Gr content has a significant impact on the diameter, porosity, and pore size. The PAN:HPMC:0.02Gr electrospun nanofiber membranes achieved excellent oil rejection (72.47%) and good permeability flux (750 LMH); this might be a result of how well the functional groups of the equally distributed Gr within the PAN:HPMC nanofibers interacted with oil. It was noticed that oil rejection dropped a lot as the Gr content went up. This is likely because the pores got wider and some of the Gr stacked or agglomerated across the nanofibers.

Immobilization of poly(hexamethylene biguanide) to cellulose acetate- and cellulose-based nanofiber membranes for antibacterial and cytotoxic studies

To develop the environmental antibacterial membrane, the physical attachments of poly (hexamethylene biguanide) hydrochloride (PHMB) on the cellulose acetate (CA) and regenerated cellulose (RC) electrospun nanofiber membranes were employed. The immobilization of PHMB increased the antibacterial efficacy (AE, %) of nanofiber membranes from 65.67% to approximately 86.13% for CA-PHMB and from 35.09% to approximately 100% for RC-PHMB. The results of the chemical and physical characteristics indicate that the degree of deacetylation of CA nanofiber, the surface charge of the nanofiber, and the density of PHMB immobilized onto the nanofiber primarily affect the antibacterial efficacy. The use of mathematical models, such as the Temkin equilibrium model for PHMB immobilization and the Monod-type model for the relationship between antibacterial activity and immobilization density of PHMB provides a deeper understanding of the interactions and kinetics involved. The rapid achievement of ∼100% AE after only 10 min of contact with Escherichia coli (E. coli) is a notable finding, indicating the quick and efficient antibacterial action of RC-PHMB nanofiber membranes. Furthermore, maintaining approximately 100% AE after 20 days of storage underscores the long-term stability of PHMB immobilized on RC nanofiber membranes. The findings suggest that RC-PHMB holds great promise as an antibacterial material for biomedical applications, food packaging industries, and filtration or treatment of water.

Adaptive Epidermal Bioelectronics by Highly Breathable and Stretchable Metal Nanowire Bioelectrodes on Electrospun Nanofiber Membrane

AbstractThe potential of the electrospun nanofiber membrane (ENM)‐based soft electronics in epidermal bioelectronics has gained huge attention with their conformal compatibility with the human body and associated performance improvements. This study presents a novel filtration‐based direct local nanowire patterning method on the ENM using dispenser systems, aiming to fabricate stretchable, breathable, and highly conductive epidermal electronics harnessing various types of metal nanowires, including Ag, Ag@Au core–shell, and Ag@(Au–Pt) core–shell nanowires. By utilizing capillary force from a support bed beneath the ENM, efficient fluid flow can be achieved, eliminating the requirement for expensive vacuum equipment typically employed in filtration processes. In the postprocessing phase, the photothermal effect of a laser is harnessed to improve the mechanical stability of the nanowire–ENM interface. The maskless fabrication process is instrumental in crafting epidermal bioelectronics in that the design can be spontaneously replicated according to diverse human body geometries in situ. The selective insulation process can be also executed with the same dispenser system, streamlining the overall fabrication system. Applications are demonstrated showcasing the advantages of the presented fabrication system and the resulting devices, including an in vivo epicardial signal recording electrode, an epidermal electrochemical biosensor, and a customized epidermal electromyography (EMG)‐based human–machine interface (HMI).